Wednesday, September 26, 2018 7:35 AM–9:00 AM ePosters

Abstract

BACKGROUND CONTEXT Surgical resection is the primary mode of treatment for primary osseous neoplasms of the spine. While resection type and margin status have been well demonstrated in primary bone tumors of the extremity, the low prevalence of these tumors in the spine makes it difficult to determine the prognostic significance of these factors for spinal tumors. We investigated the largest registry of primary bone tumors, the national cancer database (NCDB). Our hypothesis was negative margin status and radical resection would correlate with increased length of survival (LOS). PURPOSE To determine if achieving a negative margin following resection of a malignant bone tumor of the spine improves 5-year survival. STUDY DESIGN/SETTING Retrospective. PATIENT SAMPLE A total of 759 patients. OUTCOME MEASURES A total of 5-year survival. METHODS We retrospectively analyzed patients in the NCDB from 2004 to 2015 with a histologic diagnosis of primary spinal chordoma, osteosarcoma, chondrosarcoma and Ewing's sarcoma. Only patients who underwent surgical resection were included. Patients were stratified by margin of resection (negative margin vs. positive margin) and type of surgical resection (radical resection vs. local excision). The Kaplan–Meier (KM) method with statistical comparisons based on the log-rank test was used to identify univariate factors associated with LOS. RESULTS A total of 759 patients with primary spinal tumors undergoing surgical resection were identified with diagnoses of chordoma (n=332), chondrosarcoma (n=217), Ewing's sarcoma (n=112) and osteosarcoma (n=98). Following resection, 36.1% had a negative margin (n=274), 20.2% had a positive margin (n=153) and 43.7% were unspecified (n=332). Improved 5-year survival was seen with a negative resection margin (72.5% vs. 58.3%, p=.0032). Patients undergoing radical resection were more likely to have negative margins (79.8%) than those undergoing local or partial excisions (51.1%) (p CONCLUSIONS Surgical resection is the primary mode of treatment for primary osseous neoplasms of the spine, and this study confirms improved 5-year survival rates with surgical resection. Achieving a negative margin following resection improves survival. The type of resection (radical vs. local or partial excision) was not associated with survival; however, a radical tumor excision was more likely to achieve a negative margin. This study confirms the role of tumor excision in bony neoplasms of the spine, and provides evidence towards the importance of achieving a negative margin.